Electrical solenoid



A. CHURCHWARD. ELECTRICAL SOLENOID'. APPLICATION FILED IuIIE24. 1919.

Patented Sept UNITED STATES PATENT oFFlcE.

ALEXANDER, GEUECHWAED, or NEW YoEx, N. Y., AssIGNoR To WILSON WELDER a METALS COMPANY, TNC., A CORPORATION or NEW YoEx.

ELECTRICAL SOLENOID.

Specication of Letters Patent.

Patented sept. 6, 192i.

trical Solenoids, of which the following 1s a specication.

This invention is an improvement in electrical solenoids, for instance such as employed in the current-regulating apparatus of an electric welding system; andthe object of the invention is to increase the efciency and reliability of the device.

`One adaptation of the invention is illustrated in the accompanying drawings in which:

Figure 1 isav diagram of an electrical arc-welding system employing the invention;

Fig. 2 is a vertical midsection of a solenoid embodying the invention;

Fig. 3 is a perspective view ofthe upper core-spacing-and-lubricating ring; and

Fig. 4 is a perspective View of the lower core-spacing-and-lubricating ring.

In the illustrated adaptation of the invention, the solenoid coil`5 is includedv in the arc welding circuit in series with the generator 6, the carbon-pile Variable-resistance 7, and the welding electrodes 8. A lever 9 pivoted at 10 subjects the pile to compression under the lever-moment developed by the tension spring 11, while the solenoid 5 pulls on the lever in opposition to this spring, so that the resultant pile-compressing effort will always be proportionateto the preponderance of the spring etlort over l the solenoid elort. Thus-as the resistance 40 of the welding arc varies, the consequent variations of current in the solenoid pro-v duce compensative variationsin the pile resistance, all. in accordance with principles and practice now established in the art.

In such use of a solenoid it is desirable to attain the highest electro-mechanical eficiency, and .most sensitive responsiveness without sticking of the core; and my invention is directed to this purpose.

The solenoid coil 5 is wound on a nonmagnetic metal spool 12, and surrounded by the usual magnetic casing 13 of the ironclad type of solenoid. The casing has an upper annular iron pole-piece 14 and a lower hollowcylindrical iron pole-piece 15, and the entlre solenold is mounted on a suitable v bracket 16. The hollow cylindrical core 17 is connected'by a link 18 to the pile-compressing lever 9.

Upon, or in proximity to, the upper pole of the solenoid, is mounted a bearing ring 19 of sultable non-magnetic self-lubricating anti-trlction material, such as a mixture of labbitt metal and fine graphite. This bearing .ring may be secured as shown, by two clamping rmgs 2O and 21, screwed to the annular pole-piece and the coil spool. The inside of this bearing ring is smoothly pollshed and has a sliding fit on the solenoid core 17 which is also smoothly polished and slightly smaller than the bore of the solenoid spool, to afford a mechanical clearance. This bore of the solenoid spool may be also 'solenoid core in its most eiicient central positionin thesolenoid, and without stickhe invention may be embodied in different specific constructions, within its general principles and the scope of the following claims.

I claim:

1. A solenoid comprising a coil, a core working therein, and a guide ofsel-lubricating anti-friction material secured in coaxial relation with the coil and tting the core.

2. A solenoid comprising a coil, a tube therein', a core working in the tube with a clearance space, and a guide of self-lubricating anti-friction material secured in co-aXial relation to the tube and litting the solenoid core. y

3. A solenoid comprising a coil, a core working therein, and a guide of non-magnetic self-lubricating anti-friction material secured in co-axial relation with the coil and fitting the core.

4. `Ay solenoid comprising a coil, a tube therein, a core working in the tube with a clearance space, and a guide of non-magnetic rof non-magneticv self-lubricating self-lubricating anti-friction 'material secured in co-aXial relation to the tube and fitting the solenoid core. l

5. A solenoid comprising a coil, a tube therein, a core working in the tube with a clearance space, and a guide of nonmagnetic self-lubricating anti-friction material connected with the tube in co-axial relation therewith and tting the core.

6. A solenoid comprising an iron-clad coil with an annular pole-piece, a core working in the coil with a clearance, and a guide anti-friction material secured on the pole-piece and fittin the core.

7. solenoid comprising a coil, a nonmagnetic metal tube therein, a core working in the tube with a clearance, and separating devices of self-lubricating anti-friction material arranged to maintain the clearance between the tube and core members and secured to each of said members and bearing on the other of said members.

In testimony whereof I have aiiixed my signature to this s ecification.

ALEXANDER CHURCHWARD. 

